The Bush administration has won concessions from key Senate Republicans in proposed legislation on standards for detainee treatment and the rules for military trials of terrorism suspects, although some disagreements persist between the lawmakers and the White House, Senate sources said yesterday.

The disagreements that remain involve whether suspects can be convicted with evidence they are never allowed to see, an approach favored by the administration but opposed by the Republican senators. The two sides also still differ over the terms of a related amendment to the U.S. War Crimes Act that would limit the exposure of CIA officials and other civilian personnel to prosecution for abusive treatment of detainees, the sources said.

In a sign that Congress is nonetheless preparing to act quickly to establish "military commissions," as the trials are known, and provide other legal relief sought by the administration, the Senate trio at odds with the White House circulated a revised bill yesterday containing their concessions.

Senate Armed Services Committee Chairman John W. Warner (R-Va.), Sen. John McCain (R-Ariz.) and Sen. Lindsey O. Graham (R-S.C.) last week had circulated a draft that diverged more sharply from the White House's version. But President Bush's speech on the plan Wednesday, when he announced his intention to put 14 key terrorism suspects on trial, has made Senate Republicans more wary of bucking the White House.

House Armed Services Committee Chairman Duncan Hunter (R-Calif.), meanwhile, announced yesterday that he has drafted a competing bill that closely tracks the administration's preferences. He said it would be marked up by his committee on Wednesday.

Lawmakers thus will be considering three bills -- the Senate and House bills plus the administration's own bill -- that contain many provisions the administration has sought. This prospect has raised concerns among human rights groups and defense attorneys who say the plans offer inadequate protections for defendants and would set a precedent for the use of similarly worrisome rules at foreign trials of captured U.S. personnel.

The Senate bill for the first time includes language supporting the administration's position that detainee abuse can be prosecuted only if it, in effect, "shocks the conscience." Legal experts say that instead of setting an absolute standard for conduct, the bill's language would leave room for judges to weigh the urgency of the information extracted from detainees during rough interrogations.

The revised Senate bill also would bar detainees held by the United States from bringing legal action against the government to challenge the legality of their detention or treatment. It would bar the collection of damages by detainees for violations of the Geneva Conventions, which set the minimum standards for wartime treatment. Both provisions were sought by the administration, although their language is not as sweeping as the White House preferred.

The new Senate draft also requires that any evidence used at trial be declassified or summarized, a provision the administration strongly opposes. Under the measures, the military judge presiding over a trial could dismiss charges if the government refuses to turn over evidence to the defendant.

The Senate draft also contains other provisions the administration opposes, including one that would allow the prosecution of U.S. personnel for any degrading treatment of detainees and another that would prohibit the use of evidence obtained through cruel, inhuman or degrading treatment. It further defines those subject to future military trials as people engaged in anti-U.S. hostilities, a narrower definition than the White House prefers.

Senate sources said they could not predict whether a compromise or showdown with the White House is looming. Although Warner has told colleagues he expects his version of the bill to win his committee's approval and move rapidly to the Senate floor, Majority Leader Bill Frist (R-Tenn.) has said he would bring the White House version of the bill to a vote first.

Yesterday, CIA Director Michael V. Hayden went to Capitol Hill to lobby senators for the administration's version of the bill.

The dispute over detainee treatment has been particularly awkward for McCain, a former prisoner of war who is a contender for the 2008 Republican presidential nomination. Detainee treatment is one of McCain's signature political issues, and last year he forced the administration to accept a bill that prohibits cruel, inhuman or degrading treatment by the military.

Senate sources say that because of his political ambitions McCain has been wary of depending on Senate Democrats to provide the margin of victory for his provisions over White House opposition and has compromised to gain more widespread support from Republicans. A spokeswoman for Sen. Susan M. Collins (R-Maine) said she now supports the McCain bill.

Human Rights First, the Center for Victims of Torture and five other activist groups released a joint letter yesterday condemning the administration's version of the bill as "shockingly radical" and asserting that it would violate "fundamental notions of due process."